Hydraulic jarring tool with relief valve



Oct. 5, 1965 D. D. WEBB 3,209,843

HYDRAULIC JARRING TOOL WITH RELIEF VALVE Filed Sept. 11, 1962 INVENTOR D5695; 2 W555 BYM/M/ ATTORNEY United States Patent M 3,209,843 HYDRAULIC JARRING TOOL WITH RELIEF VALVE Derrel D. Webb, Houston, Tern, assignor to Houston Engineers, Inc., Houston, Tex, a corporation of Texas Filed Sept. 11, 1962, Ser. No. 222,832 1 Claim. (Cl. 175--297) This invention relates to well tools and more particiv larly to a hydraulic jarring tool incorporating a relief valve which serves to prevent rupture of packing means in the tool and to permit normal operation of such tool.

Hydraulic jarring tools have been known and utilized for many years, and while such tools have been generally satisfactory, difliculty has been experienced at times by reason of an abnormal increase in pressure in the working chamber of the tool, such increase in pressure being caused by an increase in temperature which may result from high temperatures in certain wells or by a seepage of fluid from the well into the chamber of the tool caused by a high hydrostatic pressure in the well. Even though the increase in pressure in the working chamber resulting from these factors may not in some instances be suflicient to cause rupture of the packing means in the tool, nevertheless, this increase in pressure seriously interferes with the normal operation of the tool and, therefore, this condition should, if possible, be alleviated.

As mentioned above, one of the causes of an increase in pressure in the working chamber of the jarring tool may result from seepage of fluid from the well into the tool, and while it might be assumed that if fluid may seep into the tool the same would, by the same token, leak out of the tool, nevertheless such outward leakage is not at a sufficient rapid rate to maintain eflicient operating conditions in the tool and, furthermore, it has been found that packing means frequently permits a relatively rapid flow of fluid in one direction while substantially preventing flow of fluid in the opposite direction. Consequently, it has been found that the undesirable conditions mentioned above do not, in the normal course of operations, correct themselves.

It is accordingly an object of this invention to provide a hydraulic jarring tool incorporating means to prevent an abnormal increase in pressure within the operating chamber of the tool.

A further object of the invention is the provision of a hydraulic jarring tool incorporating a relief valve communicating with the working chamber of the tool, which relief valve serves to vent fluid from the working chamber to the exterior of the tool in the event of an abnormal increase in pressure therein.

A still further object of the invention is the provision of a hydraulic jarring tool of conventional construction provided with a relief valve for venting fluid from the working chamber of the tool to the exterior of the tool upon an abnormal increase in pressure in the working chamber, such relief valve being adjustable to vary the pressure at which the same will open.

Another object of the invention is the provision of a hydraulic jarring tool provided with a relief valve for preventing an abnormal rise in pressure in the working chamber of the tool and in which such relief valve may be installed in conventional existing jarring tools without material modification thereof.

A further object of the invention is the provision of a hydraulic jarring tool provided with a relief valve for preventing an abnormal increase in pressure in the working chamber of the tool and in which the operation of the relief valve is completely automatic.

Further objects and advantages of the invention will 3,299,843 Patented Oct. 5, 1965 be apparent from the following description taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a longitudinal sectional view of a typical hydraulic jarring tool incorporating the relief valve of this invention;

FIG. 2 is a sectional view taken substantially on the line 22 of FIG. 1;

FIG. 3 is a sectional View taken substantially on the line 3-3 of FIG. 1;

FIG. 4 is a sectional view to an enlarged scale taken substantially on the line 4-4 of FIG. 1 and showing the details of the relief valve of this invention;

FIG. 5 is an end elevational view of the plunger utilized to maintain the ball relief valve in position and transmit spring pressure thereto; and

FIG. 6 is a sectional view taken substantially on the line 66 of FIG. 5.

With continued reference to the drawing there is shown, by way of illustration, a typical hydraulic jarring tool which may be of the type shown in FIG. 3 of Maxwell Patent #1,804,700 or may be of the type shown in Harrison $2 2,802,703. For the purpose of describing the purpose and operation of this invention, it is only considered necessary and desirable to illustrate and describe one type of conventional jarring tool, since the relief valve of this invention is applicable to various types of conventional hydraulic jarring tools and will operate in the same manner, regardless of the type of tool with which the same is utilized. Accordingly, the relief valve of this invention will be described in connection with the type of tool shown in FIG. 3 of the Maxwell patent referred to above, but it is to be understood that this is for illustrative purposes only and does not in any way limit the use of such relief valve to a tool of this particular type.

As clearly shown in FIG. 1, the jarring tool utilized for the purpose of illustrating and describing this invention may well comprise an elongated hollow member 10 provided at the upper end with coupling means 11 for connecting the member 10 to the lower end of a drill string 12. Secured to the lower end of member 11) by screw threads 13 or other equivalent means is an intermediate elongated hollow member 14, and secured to the lower end of member 14 by screw threads or other equivalent means .15 is a lower elongated hollow member 16. The lower end of the lower member 16 may be closed by a plug 17 threadedly connected to the member 16 at 18 and the plug 17 is provided with a central aperture 19 extending therethrough for a purpose to be presently described. The elongated hollow members 10, 14 and 16 in effect provide a single elongated hollow member com' prising one part of the jarring tool.

The second operative part of the jarring tool may be provided by an elongated hollow member 20 telescopically and slidably received in the members 10, 14 and '16 with the member 20 slidably received in the aperture 19 of the plug 17, there being packing means 21 incorporated in the plug 17 for engaging the hollow member 20 to prevent leakage of fluid through the aperture 19. Further packing means 22 may be provided in. the lower end of the upper tubular member 10 to engage the tubular member 20 and prevent leakage of fluid around such member and into the upper tubular member 10. The packing means 21 and 22 serve to provide a chamber within the tubular members 14 and 16, such chamber including a cylinder portion 23 in the tubular members 16 for slidably receiving a piston 24 formed as a part of the inner tubular member 20. The piston 24 is provided with one or more bleed passages 25 extending therethrough, and such piston 24 is also provided with a passage 26 in which is disposed a check valve 27 which serves to permit downward flow of fluid from the upper side of piston 24 to the lower side thereof, but prevents flow of fluid from the lower side of the piston 24 to the upper side thereof. The wall of the cylinder 23 is provided with vertically extending internal recesses 28 which operate in conjunction with the piston 24 to permit the flow of fluid from one end of the cylinder 2-3 to the other in conjunction with operation of the piston 24 in a manner well known in the art and clearly shown and described in the Maxwell patent referred to above.

As clearly shown in FIG. 3, the upper end 29 of the inner tubular member is provided with a polygonal portion 30 which is slidably received in a polygonal aperture 31 in a reduced portion 32 at the lower end of the intermediate tubular member 14, and this engagement between the polygonal portion 30 of the upper end 29 of the tubular member 20 and the polygonal aperture 31 in the intermediate member 14 provides for the transmission of torque between the tubular member 14 and the tubular member 20. The lower end of the tubular member 20 is provided with a coupling means 33 for attaching the jarring tool to another well tool, such as a dishing implement or the like. The upper surface 34 of the plug 17 provides a hammer for cooperating with an anvil surface provided by the lower surface 35 of the piston 24.

The jarring tool above described operates in the same manner as fully described in the Maxwell patent referred to above, and it is considered only necessary to state here that with the coupling member 33 attached to a fishing tool or the like, which in turn engages an object jammed in a well to be removed, upward pull on th drill string 12 serves to move the tubular members 16, 14 and 16 upwardly with respect to the piston 24 and inner tubular member 2th with the result that fluid contained in the cylinder 23 below the piston 24 flows through the apertures 25, thereby allowing relatively slow movement of the piston 24 with respect to the tubular member 16 until such time as the vertically extending recesses 28 are uncovered by the piston 24, at which time a relatively rapid flow of fluid takes place thereby permitting the hammer surface 34 to impinge on the anvil surface 35 and impart a sudden upward shock to the coupling member 33 for the purpose of dislodging the object jammed in the well. It is to be noted that hydraulic fluid is contained in the cylinder 23 and also in the space 36 above the reduced portion 32 of the intermediate tubular member 14, and there is a relatively free flow of fluid between the space 36 and the cylinder 23, since the engagement of the polygonal portion 30 with the poly onal aperture 31 is by no means fluid-tight.

With particular reference to FIG. 4, there is shown a passage 37 in the intermediate tubular member 14 communicating with the space 36 and with the exterior of the tool, and this passage is utilized for the purpose of supplying hydraulic fluid to the space 36 and the cylinder 23. The passage 37 may be closed by a screw threaded plug or the equivalent 38 as shown in FIG. 4. An enlarged bore 39 is provided in the intermediate tubular member 14 which terminates in a restricted passage 40 communicating with the passage 37 and through such passage communicating with the space 36. The enlarged bore 39 terminates in a valve seat 41 which may be engaged by a ball valve 42. Threadedly received in the enlarged bore 39 1s a plug 43 having a vent aperture 44 extending therethrough, and the inner end of the plug 43 is provided with a recess 45 for receiving one end of a compression spring 46. The opposite end of the compressron spring 46 receives the shank portion 47 of a plunger 48 termlnating in a head 49 having an annular shoulder 50 engaged by the compression spring 46. The head 49 of the plunger 48 is provided with a central conical recess 51 for receiving and locating the ball valve 42, and as best shown in FIGS. 5 and 6, the shoulder 50 of the plunger 48 is provided with slots 52 extending therethrough for a purpose to be presently described. The plug 43 may be provided with a wrench engaging por tion 53 to facilitate adjustment of the plug 43 in the threaded bore 39.

The plug 43 may be adjusted in the threaded bore 39 to vary the pressure at which the ball valve 42 will move away from the seat 41 to permit flow of fluid from the space 36 through the passages 37 and 40 and through the slot 52 of the plunger 48 to the vent passage 44 and to the exterior of the tool, and such pressure must, of course, be predetermined and set prior to introduction of the tool into the well. Thereafter, in the event the pressure in the cylinder 23 and space 36 exceeds the predetermined value by reason of an increase in temperature, or by reason of the seepage of well fluid into the cylinder 23 or space 36, the relief valve will operate to permit the escape of fluid and thereby maintain the pressure in the space 36 and cylinder 23 at the predetermined value in order to prevent rupture of either of the seals 21 or 22 or prevent impairment of normal eliicient operation of the jarring tool by reason of an abnormal high pressure in the working chamber provided by the cylinder 23 and space 36.

While the relief valve of this invention is relatively simple in construction, yet the same in combination with a hydraulic jarring tool provides a novel concept and also a convenient means for overcoming one of the difliculties experienced with this type of tool. As stated above, the relief valve of this invention may be utilized in connection with almost any conventional type of hydraulic jarring tool and has been described in connection with the particular jarring tool shown in the drawings for purposes of illustration only and not as indicating that the relief valve may only be utilized in connection with such a jarring tool. Obviously, the relief valve of this invention may be incorporated in a jarring tool at the time of manufacture, but the same may also be conveniently incorporated in existing jarring tools without material modification thereof, since the only requirement would be the drilling and threading of the bore 39, the formation of the valve seat 41 and drilling of the restricted passage 40 to communicate with the fluid filling passage 37 already provided in the tool. Consequently, the relief valve of this invention constitutes a very convenient and economical means for overcoming the difliculties experienced in connection with such jarring tools as a result of an abnormal increase in pressure in the working chambers thereof.

It Will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawing and described in the specification, but only as indicated in the appended claim.

What is claimed is:

A hydraulic jarring tool comprising in combination an elongated member having means at the upper end for connection to a drill string, a second elongated member having means at the lower end for connection to an object to be removed from a well, said members being telescopically and slidably related, said members being formed to provide a chamber therebetween, packing means at opposite ends of said chamber, hydraulic fluid in said cham her, a piston on one of said members slidably received in said chamber, hammer means on one of said members, and anvil means on the other of said members, valve means operatively associated with said piston for impeding movement of said piston in one direction and for permitting relatively free movement of said piston in the op posite direction, one of said members having a passage communicating with said chamber and the exterior of said tool and a relief valve disposed in said passage to bleed fluid from said chamber upon an increase in pressure in said chamber beyond a predetermined limit due to an increase in temperature and/or seepage of fluid from the Well into the chamber, whereby rupture of said packing means is prevented and normal operation of said tool is permitted, said passage comprising an enlarged portion communicating with the exterior of the tool and terminating in a restricted portion communicating with said chamber, a valve seat at the inner end of said enlarged portion, a ball valve for engaging said seat, a plug threadedly received in said enlarged portion, said plug having a vent passage therein, a plunger engaging said ball valve and a compression spring engaging said plunger and said plug, whereby the pressure at Which said ball valve will move away from said seat may be varied by adjustment of said plug, said plunger comprising a shank portion terminating in a head having an annular shoulder, said shank portion being received in said spring with said spring engaging said shoulder, said head having a central conical recess receiving a portion of said ball valve to prevent lateral displacement thereof and said plunger having passages therethrough for facilitating flow of fluid from one side of said plunger to the other, said passages comprising slots extending through said shoulder.

References Cited by the Examiner UNITED STATES PATENTS 1,697,937 1/29 Trotter 137469 1,804,700 5/31 Maxwell 175-297 2,140,733 12/38 Carroll 27759 2,166,742 7/39 Lambert 137469 2,802,703 8/57 Harrison 175-297 2,835,128 5/58 Herrstrum 29252 X 3,053,270 9/62 Campbell 137-469 3,055,388 9/62 Tabb et a1. 137--469 3,062,305 11/62 Sutliif 166-478 CHARLES E. OCONNELL, Primary Examiner. 

